The background description provided herein is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
Diesel engine operation involves combustion that generates exhaust gas. During combustion, an air/fuel mixture is delivered through an intake valve to cylinders and is combusted therein. After combustion, the piston forces the exhaust gas in the cylinders into an exhaust system. The exhaust gas may contain emissions such as oxides of nitrogen (NOx) and carbon monoxide (CO).
More and more exhaust hardware technology is being added to meet emissions on diesel applications. After treatment of exhaust gases includes the installation of multiple bricks, mixers and injectors for the exhaust stream. A diesel particulate filter is regenerated periodically to reduce the amount of soot therein. During diesel particulate filter regeneration, if the vehicle is stopped and put into park or neutral, the diesel particulate filter regeneration goes into a rich-idle state. In this state, the amount of oxygen in the exhaust is limited to protect the diesel particulate filter. Initially, the oxygen must be kept low to protect the diesel particulate filter. Restricting the amount of oxygen in the exhaust may strain the engine which may be perceived by the driver. Fuel consumption is increased during the rich-idle state. Also, the engine operates near misfire during the rich-idle state. Misfire may also be perceived by the driver.